1. Field of the Invention
The present invention relates to a pressure-adjusting mechanism which makes it possible to conveniently adjust the pressure of a pressure fluid to be supplied to an actuator such as a cylinder.
2. Description of the Related Art
A pressure control valve has been hitherto used in order to control the pressure of a pressure fluid to be supplied, for example, an actuator such as a cylinder. When the medium to be used is air, the pressure control valve functions to control the pneumatic pressure in a pneumatic pressure system depending on the purpose of use in each case.
When the secondary pressure, which is controlled by the pressure control valve, is adjusted (including, for example, the setting and the resetting of the secondary pressure), the following operation is performed. That is, for example, a pressure gauge is installed in a passage through which a secondary port of the pressure control valve communicates with a fluid pressure-operated apparatus. The secondary pressure, which is supplied to the fluid pressure-operated apparatus, is measured by using the pressure gauge. An operator adjusts the secondary pressure of the pressure control valve, while visually confirming the pointer of the pressure gauge.
In other words, in the case of the pressure control valve concerning the conventional technique, the mechanism for indicating the secondary pressure to be set is not provided for the pressure control valve itself. Therefore, it is necessary that a measuring apparatus such as a pressure gauge is simultaneously used to adjust the secondary pressure.
However, in the case of the pressure control valve concerning the conventional technique as described above, it is necessary to attach and detach the pressure gauge every time when the secondary pressure is adjusted. The attachment/detachment operation is complicated. Further, it is difficult in some cases to install the pressure gauge in the passage which makes communication between the secondary port of the pressure control valve and the fluid pressure-operated apparatus corresponding to a narrow installation environment.
A general object of the present invention is to provide a pressure-adjusting mechanism which can be constructed integrally with a pressure control valve owing to a simple structure and which makes it possible to easily adjust the pressure by an operator.
A principal object of the present invention is to provide a pressure-adjusting mechanism which makes it possible to set a desired pressure value with ease and which makes it possible to conveniently perform the setting operation for the pressure and the resetting operation for the pressure.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.